A5047972986- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Planetary Science and Exploration
- Potato Plant Research
- Galaxies: Formation, Evolution, Phenomena
- Banana Cultivation and Research
- Spacecraft and Cryogenic Technologies
- Plant Physiology and Cultivation Studies
- Computational Physics and Python Applications
University of Manchester
2020-2023
Gemini South Observatory
2006-2011
Universities Space Research Association
2011
Cerro Tololo Inter-American Observatory
2002-2006
Association of Universities For Research In Astronomy
2004
Pontificia Universidad Católica de Chile
1989-1995
The High-z Supernova Search Team has discovered and observed 8 new supernovae in the redshift interval z=0.3-1.2. These independent observations, confirm result of Riess et al. (1998a) Perlmutter (1999) that supernova luminosity distances imply an accelerating universe. More importantly, they extend range consistently SN Ia to z~1, where signature cosmological effects opposite sign some plausible systematic effects. Consequently, these measurements not only provide another quantitative...
We present UBVRIz lightcurves of the Type Ia SN 1999ee and Ib/c 1999ex, both located in galaxy IC 5179. has an extremely well sampled lightcurve spanning from 10 days before Bmax through 53 after peak. Near maximum we find systematic differences ~0.05 mag photometry measured with two different telescopes, even though is reduced to same local standards around supernova using specific color terms for each instrumental system. use models our bandpasses spectrophotometry derive magnitude...
We present well sampled optical (UBVRI) and infrared (JHK) light curves of the nearby (~18.0 Mpc) Type Ia supernova SN 2001el, from 11 days before to 142 after time B-band maximum. The data represent one best sets photometry ever obtained for a supernova. Based on synthetic using spectra 2001el 1999ee, we were able devise filter corrections BVJHK which some extent resolve systematic differences between datasets with different telescope/filter/instrument combinations. also calculated V minus...
We present optical and/or infrared photometry of the Type Ia supernovae SN 1991T, 1991bg, 1999ek, 2001bt, 2001cn, 2001cz, and 2002bo.All but one these have decline rate parameters, Ám 15 (B), close to median value 1.1 for whole class supernovae.The addition relationship between near-infrared absolute magnitudes (B) strengthens previous relationships we found in that maximum light are essentially independent parameter.(SN prototype subclass fast-declining supernovae, is a special case.)The...
We present near infrared photometry of the Type Ia supernova 1999ee; also, optical and SNe 2000bh, 2000ca, 2001ba. For 1999ee 2000bh we first-ever SN at 1.035 microns (the Y-band). K-corrections which transform in observer's frame to rest frame. Using our stretch factors derived from photometry, construct JHK templates can be used determine apparent magnitudes maximum if one has some data window -12 +10 d with respect T(B_max). Following up previous work on uniformity V minus IR loci...
We present multicolor light curves of SN 1998bw which appeared in ESO184-G82 close temporal and spacial association with GRB 980425. They are based on observations done at Cerro Tololo Inter-American Observatory data from the literature. The CTIO photometry reaches ~86 days after $U$ ~160 BV(RI)_C. U extend by about 30 previously known coverage, determine slope early exponential tail. calibrate a large set local standards common those previous studies use them to transform published our...
SN 1999aw was discovered during the first campaign of Nearby Galaxies Supernova Search project. This luminous, slow-declining [Δm15(B) = 0.81 ± 0.03] Type Ia supernova noteworthy in at least two respects. First, it occurred an extremely low luminosity host galaxy that not visible template images nor initial subsequent deep imaging. Second, photometric and spectral properties this indicate very likely similar to subclass supernovae whose prototype is 1999aa. paper presents BVRI JsHKs light...
We present optical and infrared photometry of the unusual Type Ia supernova 2000cx. With data Li et al. Jha, this constitutes largest set ever assembled for a SN, more than 600 points in UBVRIJHK. confirm finding regarding unusually blue B−V colors as SN 2000cx entered nebular phase. Its I‐band secondary hump was extremely weak given its B‐band decline rate. The V minus near‐infrared likewise do not match loci based on other slowly declining SNe, although V−K is least "abnormal." In several...
We obtained optical photometry of SN 2003gs on 49 nights, from 2 to 494 days after T(B_max). also near-IR 21 nights. was the first fast declining Type Ia that has been well observed since 1999by. While it subluminous in bands compared more slowly SNe, not at maximum light bands. There appears be a bimodal distribution absolute magnitudes SNe light. Those peak T(B_max) are all prior T(B_max), such as 2003gs, have effectively same regardless decline rate Delta m_15(B). Near-IR spectral...
Light neutralinos could be copiously produced from the decays of mesons generated in cosmic-ray air showers. These can long-lived particles context $R$-parity violating (RPV) supersymmetric models, implying that they capable reaching surface earth and decay within instrumental volume large neutrino detectors. In this article, we use atmospheric data Super-Kamiokande experiment to derive novel constraints for RPV couplings involved production light charged $D$-mesons kaons. Our results...
We present 39 nights of optical photometry, 34 IR and 4 spectroscopy the Type Ia supernova 1999ac. This was discovered 2 weeks before maximum light, observations were begun shortly thereafter. At early times its spectra resembled unusual SN 1999aa characterized by very high velocities in Ca II H K lines but low Si λ6355 line. The photometry showed a slow rise to peak brightness but, quite peculiarly, followed more rapid decline from maximum. Thus, B- V-band light curves cannot be single...
We study a class of leptogenesis models where the light neutrinos acquire their observed small masses by symmetry-motivated construction. This may naturally include three nearly degenerate heavy Majorana that can strongly mix with one another and have mass differences comparable to decay widths. find such tri-resonant neutrino system lead leptonic CP asymmetries which are further enhanced than those obtained in usual bi-resonant approximation. Moreover, we solve Boltzmann equations paying...
We present the results of a study host galaxies high-redshift Type Ia supernovae (SNe Ia). provide catalog 18 hosts SNe observed with Hubble Space Telescope (HST) by High-z Supernova Search Team, including images, scale lengths, measurements integrated (Hubble-equivalent) BVRIZ photometry in bands where are brighter than m ≈ 25 mag, and galactocentric distances supernovae. compare residuals SN distance from cosmological fits measurable properties supernova that might be expected to correlate...
We present a complete analysis of scenarios with radiatively generated neutrino masses that may occur in the minimal supersymmetric Standard Model low-scale right-handed neutrinos. For brevity, we call such model ${\ensuremath{\nu}}_{R}\mathrm{MSSM}$. pay particular attention to impact nonrenormalization theorem supersymmetry (SUSY) on loop-induced masses, by performing our computations weak and flavor bases. In particular, find smallness observed light naturally arise due soft...
We present a class of leptogenesis models where the light neutrinos acquire their observed mass through symmetry-motivated construction. consider an extension Standard Model, which includes three singlet have splittings comparable to decay widths. show that this tri-resonant structure leads appreciable increase in CP asymmetry over found previously typical bi-resonant models. To analyse such scenarios, we solve set coupled Boltzmann equations, crucially preserving variations relativistic...